Granular gases of rod-shaped grains in microgravity.

Phys Rev Lett

Institute of Experimental Physics, Otto-von-Guericke Universität Magdeburg, D-39016 Magdeburg, Germany.

Published: April 2013

Granular gases are convenient model systems to investigate the statistical physics of nonequilibrium systems. In the literature, one finds numerous theoretical predictions, but only few experiments. We study a weakly excited dilute gas of rods, confined in a cuboid container in microgravity during a suborbital rocket flight. With respect to a gas of spherical grains at comparable filling fraction, the mean free path is considerably reduced. This guarantees a dominance of grain-grain collisions over grain-wall collisions. No clustering was observed, unlike in similar experiments with spherical grains. Rod positions and orientations were determined and tracked. Translational and rotational velocity distributions are non-Gaussian. Equipartition of kinetic energy between translations and rotations is violated.

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http://dx.doi.org/10.1103/PhysRevLett.110.144102DOI Listing

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